In a memo from Deputy Attorney General Sally Yates, the Justice Department said today that it would begin working toward ending its reliance on private prisons to house federal inmates—a move that is likely to be celebrated by many as a monumental step in fixing the country’s broken prison system.

“They simply do not provide the same level of correctional services, programs, and resources; they do not save substantially on costs; and as noted in a recent report by the Department’s Office of Inspector General, they do not maintain the same level of safety and security,” Yates said in the memo.

While the DOJ emphasized that the transition will not happen overnight, it said the Bureau of Prisons has already refused to renew the contract for 1,200 beds at a private correctional facility in New Mexico. Yates mostly attributed the feasibility of winding down the use of private prisons to a declining number of federal inmates, thanks to fairer sentencing guidelines for low-level drug offenders instituted under the Obama administration.